Resource Consumption Issue in BIND Recursive Resolver by ISC
CVE-2026-19668

5.3MEDIUM

Key Information:

Vendor

Isc
Status
Bind 9
Vendor
CVE Published:
16 September 2026

Badges

👾 Exploit Exists

What is CVE-2026-19668?

A BIND recursive resolver can be subjected to excessive resource consumption when processing an overwhelming number of invalid DNSSEC records. This issue arises due to the interaction of certain DNS record types that exceed the configured limits, specifically 'max-records-per-type' and 'max-types-per-name'. Mitigation strategies involve adjusting these limits to better handle unexpected inputs, thus enhancing the stability and reliability of the resolver.

Affected Version(s)

BIND 9 9.11.0 <= 9.18.50

BIND 9 9.20.0 <= 9.20.27

BIND 9 9.21.0 <= 9.21.25

References

https://kb.isc.org/docs/cve-2026-19668
vendor-advisory
https://downloads.isc.org/isc/bind9/9.20.29
patch
https://downloads.isc.org/isc/bind9/9.21.26
patch

CVSS V3.1

Score:
5.3
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

ISC would like to thank Zuyao Xu and Xiang Li of the All-in-One Security and Privacy Laboratory, Nankai University for bringing this vulnerability to our attention.
.